HK1067514B - Lancing aid comprising a lancet that is protected against re-use - Google Patents

Description

Lancing aid including a lancet system that prevents reuse

Technical Field

The present invention relates to a lancet system for use in a lancing aid for withdrawing blood for diagnostic purposes.

Background

For various diseases, it is necessary to examine analytes contained in human blood. In many cases, only a small amount of blood in the form of a blood drop needs to be withdrawn by creating a small puncture wound. An especially important example of this is diabetes, where the amount of glucose in the blood must be detected at regular intervals. Blood may also be used to detect, for example, coagulation parameters, triglycerides, HbAlc, or lactate. Lancet systems consisting of a puncture aid and a specially made replaceable lancet are often used to create the desired puncture wound. The housing of the lancet device includes a lancet holder into which an interchangeable lancet is inserted. During a puncturing operation, the lancet holder is rapidly moved in the puncturing direction due to the puncturing drive of the lancet, the lancet is also integrally formed in the puncturing aid until the piercing tip is exposed to an exit port provided at the forward end of the puncturing aid, and the lancet forms a small puncture wound in a portion of the body against which the forward end is pressed. Thereafter, the lancet holder containing the lancet is moved back in the opposite direction from the puncture.

Small, easily operated blood collection devices, also referred to as puncture assisting devices, which are easily and reliably operated by a user and which puncture parts of the body in a virtually painless manner, are widely used today. To avoid infections, particularly in hospitals, lancets are disposable elements for single use. Once used, the lancet is discarded as waste after a puncturing operation or after being ejected from the device. In this case, the exposed needle in the waste container may cause trauma during waste disposal, thereby allowing others to become contaminated with the used lancet. Such contamination can lead to infection, and some countries plan to band blood collection systems in which the needle tip is freely available for reuse. In addition to the risk of trauma during waste disposal, there is a risk that the lancet is inadvertently reused. This is particularly important in hospitals where the lancing aid can be used for multiple patients, as the possible careless use of a nurse may result in a patient being infected with the blood of the previous patient.

In addition to the use of lancet devices by medical personnel, in so-called home monitoring use cases, the puncture aid is also used by laypersons. This particular situation is the monitoring of diabetes treatment. It was thus found in diabetes treatment that diabetes-related damage, such as blindness, can be significantly reduced when the glucose content in the blood of a diabetic patient is frequently detected and five times a day and the injected insulin is accurately adjusted based on these measurements. Penetration aids which can be used by diabetics to perform such measurements are used in home monitoring applications in order to perform such frequent measurements. The requirement for a lancet device is therefore that, in addition to simple handling when triggering a puncturing operation and painlessly creating a puncture wound, the handling of inserting a new lancet is simple and the used lancet is reliably ejected. On the one hand, the replacement of the lancet should be as simple as possible and, on the other hand, maximum safety should be ensured, avoiding inadvertent injury to the user or to others. Although a single insertion and multiple use lancet for piercing by the same user may be contemplated in a home monitoring use, even in such a case, inadvertent reuse of the ejected lancet should be avoided once the user decides to dispose of the lancet. Moreover, in waste disposal processes, in particular lancet injuries by others being discarded should be reliably avoided.

In the prior art, after the lancet is inserted, the tip of the needle is typically surrounded by a tip cap made of plastic for safe insertion of the lancet. After the lancet is inserted, the tip cap may be removed so that the tip of the needle is exposed for the lancing operation (see US 5628765). However, there is a risk of inadvertent injury and damage to the needle tip due to the exposed needle tip. After one or more puncturing operations, the lancet is removed from the lancing aid. This can be done manually, in which case there is a high risk of injury by the needle tip or the automatic ejection mechanism.

EP0565970 discloses a lancet device in which a lancet is ejected from a lancet holder by means of an ejection lever. The user can operate the ejection lever by pressing the corresponding button.

Furthermore, in the patent document US4442836 a firing mechanism is described in which the needle is automatically released when the puncture aid is reinserted, in order to allow the used lancet to be discarded after each puncture operation. Such an ejection mechanism provides a high degree of additional engineering. Moreover, many uses of the lancet systems that have been inserted are not available, particularly in home monitoring applications where consumers desire. Another major drawback of said prior art is that the tip of the needle is not protected after ejection of the lancet, which leads to the above-described risk of injury.

To facilitate safe removal of the used lancet, the blood collection systems described in the prior art ensure that the needle tip is protected after ejection of the lancet. This is considered to be an important function especially for elderly or visually impaired patients and patients with hand trembling caused by illness.

By forming the lancet integrally with the puncture aid cover, a prior art needle tip protection can be achieved, so that the lancet and the housing cover together form a replaceable disposable unit. Such designs are described in EP0595148, US4990154, US5454828, DE 10053974. When the lancet is ejected by the user, the housing cover rests on the piercing tip so that the lancet enclosed by the cover can be subsequently discarded. Even if the cap needle tip is protected by the mechanism after ejection, an inattentive user will reinsert the already ejected needle and perform a new piercing operation. The user is thus instructed to recognize that the needle has been used.

Only document EP0630609 discloses a mechanism that directly prevents reinsertion and thus the reuse of the ejected lancet.

The lancet device includes a needle with a needle body that breaks when the needle is ejected from the lancing aid to prevent reuse of the needle. This prevents the user from reusing the contaminated needle. However, this prior art has the disadvantage that the needle tip is not protected after the needle has been ejected.

Disclosure of Invention

It is an object of the present invention to provide an easy-to-use piercing aid, preferably for home monitoring applications, which prevents reuse of an already ejected lancet system and also ensures that needle-tip injuries are avoided after ejection of the lancet system. Advantageously, the needle of the lancet system that has been inserted can be easily reused.

This object is achieved by a puncture aid and a lancet system according to the independent claims. Preferred embodiments derive from the dependent claims.

The present invention relates to a lancet system and a penetration assisting device comprising the lancet system. The lancing aid has a housing for insertion of a lancet system. The housing also has an opening through which the needle tip emerges from the housing and a drive mechanism to perform a puncturing operation. According to the invention, the housing also has a retaining element which interacts with a corresponding retaining element of the lancet system once the lancet system is inserted into the puncture aid. The interaction between the retaining elements causes the lancet system to be positioned in the housing at a defined location. The precise positioning of the lancet system is particularly important for the drive mechanism for the penetration aid, since this is the only way in which the needle is correctly coupled to the drive mechanism so that the needle performs the penetration operation at high speed and with little vibration. This allows the needle to penetrate the desired part of the body quickly and relatively painlessly. In addition to the holding element, the lancet system for a penetration aid comprises at least one needle having a piercing tip adapted to form an opening in the skin. The needle is connected to the needle body and the at least one protective portion of the needle body and the needle are movable relative to each other. In the first position the needle tip is at least partly surrounded by the protective part of the needle body, and in the second position the protective part of the needle body and the needle tip are arranged opposite each other such that the needle tip can be released from the protective part of the needle body. If the protective part of the needle body is in its first position, it prevents injury from the lancet tip, which is particularly important after the lancet system has been launched out of the lancing aid.

The needle body further comprises a blocking mechanism that is activated by interaction with the penetration assisting device. The blocking mechanism modifies the needle body in such a way that, after the lancet system has been ejected from the puncture aid, the holding element on the puncture aid no longer interacts with the holding element of the lancet system when the lancet system is reinserted again. In this respect, the blocking mechanism can be automatically activated as soon as a specifically perceived operating step is performed on the penetration aid. However, other embodiments are contemplated in which the user actuates the blocking mechanism through a separate operating step.

Because of the special structure of the needle body, the lancet system according to the invention provides protection for the tip of the needle, which is surrounded by a protective part of the needle body after ejection from the lancet system, in order to prevent injury caused by the tip of the needle. The blocking mechanism also affects the interaction of the retaining elements. Within the scope of the present invention, the term "interaction of the retaining elements" includes any conceivable embodiment known from the prior art for inserting and positioning a lancet or a storage housing in a puncturing aid. For example, the holding element can snap or clamp quickly. Suitable retaining elements for this purpose can be designed, for example, as locking lugs, grooves or hooks, in order to designate several possible embodiments. Similar to the systems described in the prior art, which comprise separate lancets, it is also conceivable that the lancet system already is sufficiently positioned and held in the puncture aid as a result of its coupling to the drive unit, so that the drive unit itself can serve as a holding element for a lancet system of suitable design.

If a plurality of retaining elements are provided for positioning the lancet system, the blocking mechanism advantageously prevents an interaction between the lancet system and the retaining elements of the piercing aid, so that the lancet system cannot be retained and positioned in the piercing aid. This is particularly advantageous when both the lancet system and the puncturing aid have a plurality of retaining elements which act independently of one another.

In a preferred embodiment, the interaction of the retaining elements is blocked in such a way that a reinsertion of the lancet system into the piercing aid is prevented. Within the scope of the present invention, the term "reinsertion" includes the operation of the lancet system such that the lancet system is positioned in the puncturing aid at a location where a puncturing operation is desired and whereby the interaction of the retaining elements is maintained there. To this end, the lancet system is reused in its initial position, thereby preserving the initial state of the lancet system and the puncture aid that is present when the puncture aid is first used.

When operating the puncture aid, the user can advantageously immediately and clearly identify the lancet system that has been used, since, for example, a reinsertion of the lancet storage housing into the puncture aid is prevented. In contrast to the prior art, the user does not need to deliberately distinguish between a used lancet system and a new lancet system. Advantageously, the user is free from unnecessary reinsertion of the used lancet system, which no longer affects blind patients and the elderly who are often difficult to find the above fact.

However, the blocking mechanism may also only prevent operation of the lancet, in which case the lancet that has been used may be reinserted. If re-insertion of the lancet system is prevented, this usually means that the lancet system cannot be coupled to the drive unit.

In a preferred embodiment, the blocking mechanism is substantially realized by deformation of the needle body. This proves to be particularly advantageous when the shape of the needle body itself forms at least a part of the holding element. The deformation of the needle body may also spatially separate the holding element in the penetration aid, so that the blocking means has an indirect effect on the holding element without acting directly thereon. In this way, the lancet system is no longer positioned and held in a defined position in the puncture aid. In a preferred embodiment, the deformation of the needle body causes the protective portion of the needle body to move to the first position so that there is no risk of injury when disposing of a used lancet. The protective portion of the needle and the blocking mechanism are thus implemented as a single component of the lancet system.

In principle, the retaining elements may interact in various ways. The blocking mechanism may have a direct or indirect effect on the retaining element. In the case of direct action on the retaining elements, at least one retaining element is advantageously deformed, covered or destroyed in such a way that the retaining elements can no longer interact with one another. Further embodiments are contemplated for positioning the lancet system in the lancing aid due to the magnetic properties of the system. In this way, the change in the magnetic properties of the needle body may prevent reuse of the lancet system. Thus, a suitable magnetic element of the needle or the penetration assisting device is a holding element of the system.

Because the blocking mechanism advantageously only prevents repeated insertion of the lancet system, and does not prevent reuse of an already inserted needle, the lancet system also meets the requirements of home monitoring applications where multiple uses of an inserted needle are often required.

The lancing device according to the invention for collecting blood has a drive unit with a plunger which moves a needle from its rest position into a lancing position. A number of drive mechanisms are known in the art which may be used in the field of blood collection devices (e.g. US5314442, WO00/02482, US 3030959). In particular, a drive mechanism is often used to extract energy from a previously tensioned spring. A drive unit is preferably used within the scope of the invention which causes a guided movement of the plunger and the needle forming a mating coupling, as described for example in DE 10053974. The guided movement of the needle by means of the guide block is described in the above-mentioned EP 0565970. These drive mechanisms are preferred because the penetration process is less painful. However, the system according to the invention is not limited to a specific drive mechanism, but various drive units may be combined.

An important aspect of the invention is a lancet system which can be detached from a drive unit containing at least one needle, wherein the lancet system is provided as a disposable unit. In this respect, the term "needle" includes blade-shaped substantially flat puncturing units as well as any other conceivable embodiment. In principle, needles that can be used in the present invention are basically known from the prior art and can be used in lancet systems. In the prior art, the needle is usually combined with a base body, which is coupled to the penetration aid, which is referred to as a lancet. Such lancets typically have a base body made of plastic, wherein the metal needle is discarded. Such a lancet may be incorporated into a lancet system of the present invention in accordance with the present invention. For example, it is conceivable that the needle body of the invention comprises a base body similar to the one used in the prior art, wherein the inventive functionality of the system is maintained by the incorporation of the base body. In this case, the needle body has a structure of at least two parts according to the above-described embodiment. In a preferred embodiment, the needle body is designed such that a plurality of lancets is arranged in the needle body, which represents a storage housing containing a plurality of lancets, and each base body of a lancet represents a part of the needle body. In a preferred embodiment, the protective part of the needle is thus formed by the storage housing shell. The needle and the base body may be movably guided into the storage housing. In the needle body designed as a storage housing according to the invention, the needle is preferably arranged in a separate chamber in order to prevent contamination of the unused needle by the used needle during the refilling process.

In order to perform a puncturing operation, a portion of the needle body is advantageously designed like the system described in DE10053974 above, so that the individual needles of the system can be operatively coupled to the drive unit of the puncturing aid. Examples of embodiments which can be used for driving a needle in a storage housing of a penetration aid are for example DE10053974, US4990154, US 5074872. The chambers arranged next to one another, in which the lancets are arranged separately, are positioned successively relative to the drive unit in order to carry out the puncturing operation in such a way that in any case a single needle can be coupled to the plunger of the drive unit. Also in this case, the storage housing in the form of a cartridge contains a cavity in which the needle is arranged parallel to the axis of the cartridge, which proves to be particularly advantageous.

The lancet system further advantageously comprises a needle body, the tip of which is at least partially surrounded by a protective portion of the needle when the needle is in its rest position. To perform a puncturing operation, the protective portion of the needle body is spatially separated from the needle tip so that the protective portion of the needle body does not obstruct the puncturing operation. When the lancet system is ejected from the puncture aid, the puncture aid remains in its rest position to protect the ejected needle tip, and additionally the blocking mechanism of the present invention prevents reuse of the lancet system. However, the protective portion of the needle body may not move to its first position until the lancet system is ejected, so that the needle tip is protected only by the ejection. In a preferred embodiment, the unused needle is also in a rest position prior to insertion into the penetration aid, in order to prevent injury and contamination by the needle tip when the needle is inserted and after ejection.

The blocking mechanism of the present invention is actuated when the lancet system is ejected from or inserted into the lancing aid independently of the lancet tip protector. In principle, the blocking mechanism or the needle tip protector can be activated separately or by means of a separate operating step of the lancing aid in the lancing operation. In general, all possible combinations ensuring a continuous or simultaneous protection of the blocking means and the needle tip are conceivable.

The blocking mechanism may have a variety of configurations, but advantageously the shape of the needle is altered in such a way that once it is ejected, the needle cannot be reinserted into the lancet system. For example, the blocking mechanism may move at least a portion of the needle body that interacts with the lancing aid such that a change in its position prevents reinsertion of the lancet system. This is the case, for example, when the blocking mechanism closes off a recess in the needle body forming the holding element or a recess is formed in the needle body which is important for the interaction of the lancet system and the puncture aid. Additionally, the blocking mechanism may include a predetermined rupture point that causes the needle to rupture when fired in the lancet system. It is also contemplated that the needle may be enlarged, reduced, or bent, with only some methods deforming the needle.

According to the invention, the interaction between the lancet system and the piercing aid activates the blocking mechanism and sets a first position of the protective portion in which it at least partially surrounds the piercing tip.

An important requirement of lancet systems is that the needle tip used to form a wound on an appropriate part of the body be sterile. The sterility of the needle tip must be ensured over a long period of time, i.e., the period of time from the manufacture of the lancet system to its use. Sterility can be achieved during manufacture of the lancet system by using gamma rays as is well known in the art. To maintain sterility, the lancet system is sealed in a package, such as a polyethylene bag. In another embodiment, the lancet tip exposed from the protective portion of the needle body upon opening of the lancet system can be closed by a sealing foil, for example. A removable sealing foil that is removable by the user prior to use of the lancet system is a preferred removable sealing foil. However, a thin foil that is not pierced by the needle tip until the needle is used may be used so that the user does not perform additional handling steps. Such foils may become part of the manufacturing process of the lancet system, which is typically manufactured by means of an injection molding process.

Furthermore, in the prior art, an elastomer for sterile protection is disclosed in WO 01/66010, which encapsulates the needle tip and thereby protects it from contamination. The sterile protector may be pierced during the puncturing operation or removed by the user prior to use.

In a further advantageous embodiment, the protective portion of the needle body may comprise a sterile protection and/or the protective portion may be substantially formed by it. In this case, the elastomer of the sterile protection can, for example, serve as a protective part for the needle body on the basis of the fact that the needle tip moves in a guided manner relative to the elastomer. Another portion of the needle body that can be actuated independently of the sterile protector can alter the needle body and represent a blocking mechanism. This requires a sterile protector to be reversibly exposed to and surrounding the needle tip in order to protect the needle tip, in the case of elastomers with a sterile protector (WO 01/66010), the elastomer is initially pierced in the piercing operation and the needle tip is subsequently retracted into the elastomer. Thus, in this example, the needle tip changes its position relative to the sterile protection during the puncturing operation, and the needle tip is protected by the sterile protection in its rest position after the puncturing operation. In principle, many embodiments of sterile protections are conceivable, and the system of the invention is not limited to any particular embodiment of a sterile protection.

Drawings

The system according to the invention is described with reference to the following figures and embodiments, which are not limited to this individual embodiment.

FIG. 1 shows a two-part system;

FIG. 2 illustrates the lancet system with the blocking mechanism activated during the puncturing operation;

FIG. 3 illustrates a lancet system with a blocking mechanism activated when the system is fired;

FIG. 4 illustrates a lancet system with a blocking mechanism to prevent coupling of the penetration aid with the lancet system;

FIG. 5 illustrates the lancet system with the blocking mechanism activated when the lancet system is inserted into the penetration aid;

FIG. 6 illustrates the lancing aid with a lancet storage housing; and

fig. 7 shows a lancet system with a blocking mechanism that widens the needle body.

Detailed Description

Fig. 1 shows a lancet system 1 in substantially two parts. Fig. 1b and 1d show cross-sectional views of the lancet system, respectively, and fig. 1a and 1c show the situation before and after use, respectively. The system has a needle 3, the front tip of which is packaged in a sterile manner with an elastomeric protector 4. Such an elastomer ensuring sterility of the needle tip is known from document WO 01/66010, which is incorporated by reference. The metal needle 3 is attached to the plastic body 2b and permanently connected thereto. The plastic body has a rear portion 6 that couples the lancet system to the drive plunger for movement of the needle along axis 8 in the puncturing direction. The rear part 6 of the plastic body, which is part of the needle body, comprises two arms which are connected in a mating manner during the puncturing operation by means of a protrusion 11 with a plunger of a (not shown) puncturing aid. The co-operating form-fit connection between the drive plunger and the lancet is described, for example, in DE10053974, which is incorporated by reference. Of course, any other prior art coupling mechanism is contemplated for accomplishing this penetration operation. The needle 3 and the plastic body 2b permanently connected thereto are movably mounted in the plastic body 2a, which represents a protective part of the needle body. The needle and the second part 2b of the needle body are movable in the needle body in the puncturing direction. The protective part 2a of the needle body has a lower wall 10 with a hole 9 from which the needle tip emerges during the puncturing operation. The needle body also has an opening 7 at its upper end, through which opening the drive plunger of the lancing aid is inserted into the needle body in order to connect with the second part of the needle body in a form-fitting manner and perform a lancing operation. The protective part 2a of the needle body also has two recesses 13 and 14 in order to lock it in the second part of the needle body 2 b. In order to engage the second part of the needle in the protective part, the rear part 6 of the second part of the needle also has a locking lug 12 which engages in a recess 14 in the first rest position of the lancet system before use and which holds the second part of the needle due to the extension arm 6. The middle of the guard portion and the second portion of the needle body have tapered channel-shaped bodies 5 and 5 'so that the tapered portions 5 and 5' fit together precisely in a first resting state prior to use of the lancet system, the lancet system in this position having the configuration shown in fig. 1 a.

To perform a puncturing operation, a plunger (not shown) of the puncturing aid is engaged in the lancet system through the opening 7, wherein the plunger is connected in a form-fitting manner with the arm 6 of the second part of the needle body. Thus, the arms 6 are pressed together so that the lugs 12 of the arms 6 are no longer engaged in the recesses 14 and the needle can be moved forward in the puncturing direction 8. In this process, the elastomer protector 4 is first pressed against the lower wall 10 of the needle body 2 a. If the puncturing operation continues, the needle is driven through the elastomeric protector and is thereby exposed from the opening 9 in the lower wall 10 and forms a wound on the desired part of the body. The elastomer protector 4 is at the same time stopped by the wall 10, so that the front portion 15 of the second portion of the needle 2b corresponding to the recess 16 can move over the elastomer protector. After completion of the puncturing operation, the needle body 2b and the needle are subsequently withdrawn into the protective portion 2a due to the co-operating coupling with the drive plunger. Once the rear arm 6 is in the protective part 2a of the needle, the lugs 12 engage in the recesses 13 of the needle 2a when the needle 2b is pulled back. The lancet system is now in a second rest position after the puncturing operation. In this position, the second part of the needle body 2b protrudes from the opening 5 of the protective part of the needle body 2a in such a way that it is deformed in this area. The tapered portions 5 and 5' no longer fit together. In a correspondingly designed lancing aid, the insertion of the lancet system is only allowed when the tapered portion 5 of the needle is fully formed as shown in fig. 1a, the insertion of the lancet system already in use being blocked as a result of the situation shown in fig. 1 c.

The example shown in fig. 1 has a blocking mechanism and allows the protective part of the needle to be moved to the first position during the puncturing operation. When the lancet system is ejected after the needle has been used, the shape of the system has changed in such a way that it is not possible to reinsert the lancet system into a properly configured puncture aid. Furthermore, the needle tip is completely surrounded by the protective part, so that there is no risk of injury to other persons during e.g. waste disposal.

Fig. 2 illustrates a lancet system in the form of a generally circular lancet storage housing. In contrast to fig. 1, only the protective part of the needle body 2a is designed as a storage housing in order to guide a plurality of needles 3 movably therein.

Fig. 2a shows the exterior of the storage housing. The storage housing forming the protective part of the needle has a similar structure as in fig. 1 and has recesses 13 and 14 in which the locking lugs 12 of the corresponding second part of the needle 2b can engage. The lancet system has a storage housing axis 21, which is arranged concentrically with the protective part of the needle body, and serves as a support for the lancet system in the puncturing aid. The lancet system can be rotated about an axis 21, so that in each case one needle can be positioned relative to a drive unit (not shown) in the puncture aid. Similar to the lancet system shown in fig. 1, the lancet system shown in fig. 2 also has a tapered portion 5 in the form of an opening in the protective portion of the needle body 2a, wherein the opening is substantially tightly closed by the second portion of the needle body 2 b.

FIG. 2b illustrates a cross-sectional view of the lancet storage housing shown in FIG. 2 a. This system has a similar structure to that of fig. 1, but it is constituted by a plurality of needles provided with a second portion of the relative needle body 2 b. The lancet system shown in fig. 2 therefore has a plurality of parts, including an outer protective portion of the needle body and a plurality of second portions 2b of the needle body. Fig. 2c and 2d show the lancet system after use, wherein all the needles of the lancet system have been used. Of course only a portion of the needle may be used in the lancet system. In this case the second part 2b of the needle projects through only some of the openings 5 of the protective part of the needle 2a, while the other openings are tightly closed by the needle as shown in fig. 2 a. Depending on the interaction of the lancet system with the penetration assisting device, embodiments are conceivable in which the re-insertion of the lancet system into the penetration assisting device is prevented once some of the needles have been used, or only after all of the needles in the lancet system have been used completely. Advantageously, it is also contemplated that a partially used lancet may be reinserted into the penetration aid when the system is positioned relative to the drive plunger such that only an unused lancet may be used by the system.

Fig. 3 shows a rectangular needle body comprising a plurality of needles in the form of a reservoir housing. The protective part of the needle body 2a also has an opening 9 in its lower end 10, from which the needle emerges for performing the puncturing operation. Although in its rest position, i.e. when no puncturing operation is performed, the needle tip (not shown) of the needle is in a protective part of the needle body 2a, wherein the needle is movably guided. The needle body 2a contains a groove in the lower part 34 close to the lower end 10 of the needle body, which makes it easy to grasp and facilitates handling by the user. A recess 33 is provided in this lower part 34 as a retaining element which, within a suitably designed puncturing aid, locks the lancet system in the puncturing aid during insertion. The blocking means 31 is positioned in the middle of the needle body 2a as a part of the needle body 2a and is movably guided to the upper part 35 of the needle body 2a and is first held in the activated position by a spring-loaded arm 39. The recess 32 in the upper part 35 locks the blocking means 31 when the blocking means 31 is guided along the upper part 35 of the needle body.

Fig. 3b shows the lancet system after use. As shown in fig. 3b, the blocking means 31 surrounding the needle body 2a in the form of a ring is now positioned at the upper end of the needle body so that the blocking means 31 widens the needle body section 35 at this location. Once the blocking mechanism 31 is locked in its position, the lancet system is then no longer allowed to be reinserted due to the enlarged needle.

Fig. 3c and 3d illustrate in detail the operation of the blocking mechanism 31 for the lancet system described above. To lock the blocking mechanism 31 in the upper part 35, the blocking mechanism has a locking arm 36 which engages in the recess 32. In the position shown in fig. 3c and 3b, the locking arm 36 is spring-loaded against the lower edge of the recess 32 in order to prevent displacement of the blocking mechanism 31. The stop 37 also acts as an additional abutment flange for the blocking means 31 against a protrusion 38 in the upper part 35 of the needle part. When the storage housing is inserted into the penetration aid housing 70 for first use as shown in fig. 3e, the rear portion 35 of the storage housing is positioned in a suitably tapered portion 82 of the housing 70. Instead, the forward portion 80 of the housing 70 widens so that the widened diameter portion of the lancet system is disposed within the lancing aid housing due to the loop acting as a blocking mechanism. In this position, the lancet system is held in the puncture aid in such a way that a drive unit (not shown) of the puncture aid can be engaged in the storage housing in order to be coupled to a needle of the lancet system. The lancing aid housing also has two stops 83 and 84 which in this position of the lancet system are adjacent to the blocking mechanism 31 in the lancing aid. If the lancet system is removed from the lancing aid housing after use, the stop 84 initially has the effect that the blocking mechanism 31 remains fixed in place in the lancing aid housing while the storage housing is pulled out of the region 82 of the lancing aid. Thus the blocking means 31 is pushed along the needle to the upper part 35 of the needle. In the process, the blocking mechanism 31 is locked with the needle and the projection 38 and the stop 37 also prevent movement of the blocking mechanism along the needle. If the blocking mechanism 31 rests on the projection 38, the other pulling movement on the reservoir housing shell overcomes the resistance of the stop 84 and the reservoir housing can be detached from the lancing aid. The reservoir housing is now outside the housing in the used state as shown in fig. 3b, wherein the blocking mechanism 31 is permanently positioned on the needle due to the locking hook 36 and the stop 37. If the lancet storage housing is reinserted into the lancing aid housing, the storage housing can no longer be pushed into the tapered region 82 of the lancing aid housing due to the peripheral widened upper portion 35 of the needle body. Thus, positioning of the lancet system in its initial position in the puncture aid is no longer possible. The lancet system is no longer held in the piercing aid. The coupling of the individual needles to the drive unit of the lancing device for carrying out the lancing operation is prevented. Moreover, after the lancet system has been fired, the user can easily observe that the lancet system is a used system due to the displacement of the ring. For this reason, it is also conceivable to make the blocking means 31 more prominent with color.

As an alternative to the described change in the needle body 2a, it is also conceivable that the blocking mechanism 31 is movable on a recess 33 of the lancet system. In this case, a reinsertion of the lancet system in the puncture aid is prevented, since the lancet system is no longer locked in the puncture aid. Other embodiments using movably mounted blocking mechanisms, for example, resulting in a reduction in the size of the upper portion 35 of the needle body, are also contemplated. In this case, an unused lancet system, for example in the state shown in fig. 3b, is initially provided in the lancing aid. A used lancet system is characterized in that the blocking mechanism 31 is pushable on the needle body part in such a way that the upper part 35 of the needle body 2a is reduced in size. Thus, fig. 3a shows the system after it has been ejected. A correspondingly designed puncturing aid can, for example, have a retaining element which no longer interacts with the lancet system, which is modified in such a way that it is not possible to reinsert the lancet system in the puncturing aid. The blocking mechanism and the locking element of the needle body 2a have to be adapted according thereto. Moreover, it is also contemplated that the movable blocking mechanism 31 ensures that reinsertion of the lancet system is prevented and also protects the piercing tip. In this case, after the puncturing operation, the needle tip is not retracted into the protective portion of the needle body as shown in fig. 3. Thus, the needle tip is not automatically protected in the rest position. Thus, no protection of the needle tip is ensured until after the lancet system has been ejected from the puncture aid. According to the blocking mechanism as shown in fig. 3a, the movement of the blocking mechanism 31 lengthens the needle body in the region of the needle tip, so that the needle tip is surrounded by the blocking mechanism in a protective manner, while the blocking mechanism is activated due to the deformation of the body. In this case, a part of the needle body acts as a blocking mechanism and also as a protective part of the needle body surrounding the needle tip region when the lancet system is ejected. The protective part of the needle body and the blocking means thus comprise the needle body of a single structural part.

Fig. 4 shows a rectangular lancet system in which a plurality of needles are positioned in the cavity 42 of the protective portion of the needle body 2 a. The upper part of the protective part of the needle has a blocking means 41 in the form of a push button which is located on the protective part of the needle and which is movable in a direction 45 towards the protective part of the needle. The upper portion of the button has a guide groove 49 which engages in a mating lip (not shown) of the lancing aid so that the lancet system can be fixedly positioned in the lancing aid. Once positioned in this way, the drive plunger (not shown) of the penetration assisting device is coupled with the rear region 48 of the needle 3 in order to perform the penetration operation. For this purpose, the needle is moved in a direction 43 relative to the protective part of the needle body and the tip of the needle is exposed from the protective part 2a of the needle body. In the described system, the needle is returned to the storage housing after the puncturing operation and the needle tip is retracted into the needle body 2 a. The movement of the plunger in direction 44 by the drive of the puncturing unit causes the storage housing to move to the next position until the plunger is coupled with a needle positioned in the adjacent cavity 42 in order to perform a new puncturing operation. If the lancet system has to be replaced in the lancing aid, the drive plunger has to be moved first outside the rear region 46 of the needle body 2 a. Furthermore, the storage housing is moved to the next position and due to the inclination of the housing of the lancing aid, the push button 41 is pressed down simultaneously. Button 41 is now moved within the lancet system as shown in fig. 4c and 4d so that a segment 50 of the button protrudes from the bottom of needle 2 a. In this position, the recess 47 of the push button 41 engages with the rear region 48 of the needle 3, which prevents the puncture aid from being coupled again with the lancet system, as shown in the front view of fig. 4 d. Thus, no puncturing operation can be performed using the lancet system shown in fig. 4c and 4 d. Moreover, due to the deformation of the needle body in the region 50, the lancet system cannot be reinserted into the lancing aid. The lancet system can therefore not be positioned by means of the guide groove 49 as part of the holding element.

Fig. 5 illustrates a circular lancet system that also contains multiple needles in the needle body. Similar to fig. 2, the lancet system has a multi-part needle body. The channel 52 is disposed along the axis of rotation of the lancet system and the plug 53 is located in the channel at the forward end of the lancet system. The plug 53 is held in the first position by the deployment retention arm 56, and this position represents an unused state of the lancet system. The retaining arms 56 engage in tapered portions of the plug 53, which are formed by mutually inclined planes 55 of the plug. When the lancet system is inserted into the puncture aid 70, the plug 53 is pressed into the channel 52 towards the piercing tip by means of the centering plunger 57 of the puncture aid. When the plunger is pressed in, the retaining arms 56 are spread apart due to the inclined plane 55 of the plug 53. When the retention arm 56 of the lancet system is deployed, the plunger 57 may be engaged therebetween. Thus, the plunger 57 may be almost fully inserted into the lancet system and used as a support to position the storage housing. The appropriately designed drive unit of the puncturing aid is thus oriented relative to the lancet of the system such that it is coupled to the lancet and can perform a puncturing operation. After the storage housing has been used, it can be removed from the lancing aid. To this end, the plunger 57 is pulled out of the interior of the storage housing shell, while the plug 53 remains in the region of the lower end of the storage housing at the needle tip. Thus, a used lancet system may be designed as shown in fig. 5c, wherein the plug 53 is no longer retained in the upper portion of the retaining arm 56. If an attempt is made to insert a used lancet system into the lancing aid, the plunger 57 hits the upper portion of the undeployed retaining arm 56, thereby preventing insertion of the plunger into the lancet system. The absence of the plug 53 prevents the plunger 57 of the lancing aid from deploying the retaining arm and thereby disabling the lancet system from being placed on the lancing aid.

Fig. 6 illustrates another embodiment of a lancet system disposed within a lancing aid. Fig. 6a-6d initially illustrate a lancet system similar to that of fig. 1. Similar to fig. 1, the system shown in fig. 6 also has an elastomer 4 surrounding the needle tip in a sterile manner and a two-part needle body with a tapered portion 5 and 5' in its middle. The movement of the second part 2b of the needle, which also has an arm 6 at its rear, which is coupled in a mating manner with the plunger 78 of the penetration aid 72, is guided inside the protective part 2a of the needle. As shown in fig. 6c and 6d, the plunger 78 engages with the head 71 in the second part 2b of the needle body and moves the needle along the axis 8 of the penetration direction. In the process, the arms 6 of the needle body 2b are pressed together and the projections 11 engage behind the grooves in the head 71. The lancet system operates in a mode similar to that shown in fig. 1, and therefore only its interaction with the lancing aid is described herein. The lancing aid 72 has a locking lever 74 which is mounted in the lancing aid and is rotatably pivotable on a shaft 75. The locking lever 74 has a circular shape in a first region 77 so that it is matingly engaged in the tapered portion 5 of the lancet system.

Fig. 6a shows the state of the lancing aid with the lancet system in the inserted state before use. If it is desired to use the lancing aid for a lancing operation, the locking lever 74 is rotated through a 90 degree angle, either automatically or by the user alone, upon triggering of the lancing operation, so that the lower portion 77 of the locking lever no longer engages in the tapered portions 5 and 5'. The rotation of the locking lever is ensured by the fact that the lancing aid further comprises a recess 76 in its housing, which causes the locking lever to rotate about the rotation axis 75. When performing a pricking operation, the second part of the needle body 2b is displaceable along the protective part of the needle body 2a, and a part of the needle body 2b is exposed from the opening of the needle body 2a and is not hindered by the locking bar 74. In the process, the piercing tip may drive through the outlet 9 of the elastomer and lancet system and through the outlet 73 of the penetration assisting device.

After the puncturing operation the needle returns to its rest position, however during this the second part of the needle is locked in the recess 13 of the protective part of the needle. This results in a deformation of the needle profile in the area of the tapered portion 5 due to the second part of the needle 2b now emerging from the opening of the needle 2a, as shown in fig. 1. After the lancet system is removed from the lancing aid, the locking lever 74 rotates back to its initial position as shown in fig. 6 a. As shown in fig. 6d, the locking lever 74 prevents the lancet system from being reinserted into the lancing aid. The locking lever 74 is no longer engaged in the tapered portion 5 of the used lancet system because the tapered portion 5 is partially enclosed by the second portion of the needle body 2 b. Thus, the lancet system is no longer positioned and maintained in its initial position. The plunger 78 is no longer engaged in the lancet system. Preventing the head 71 and the projection 11 from forming a mating connection.

Fig. 6e-6h illustrate an embodiment similar to fig. 6a-6d in which the lancet system includes a plurality of needles that are stored in a storage housing in the manner shown in fig. 2. As mentioned above, the principle of operation is the same and can be easily converted from a system with one needle to the system shown in fig. 6e-6 h. In this respect, the invention has only been described in relation to embodiments allowing the reinsertion of a storage housing in which the needle is only partially used. To do this, the user must rotate the storage housing relative to the penetration aid housing until the locking lever 74 can engage in the tapered portion 5 which is not blocked by the needle 2 b. The positioning of the lancet system relative to the puncturing aid and thus the drive plunger ensures that only an unused lancet is available for the next puncturing operation. The advantages of a lancet system that rotates in only one direction and no more than one direction through 360 degrees of rotation of the lancet system can be incorporated as desired in order to prevent reuse of a puncture aid that has already been used.

Fig. 7 illustrates another embodiment of a lancet system in the form of a non-circular storage housing. The needle structure has portions similar to those of the previous figures. The sterile protector and the needle are arranged in the above-described manner, and therefore a detailed description is omitted here. Similar to the system shown in FIG. 5, the blocking mechanism shown in FIG. 7 is activated upon insertion of the lancet system into the lancing aid. For this purpose the needle body 2a has a blocking means 31 in the form of an outer ring not surrounding the upper part 35 of the needle body. When positioned in this position, the blocking mechanism 31 substantially covers the resilient arms 90 located at the upper portion 35 of the needle body. The resilient arms 90 are thus pressed into the recesses 95 of the needle body 2 a. The blocking means 31 also has a circular protrusion at its lower end in order to enlarge the circumference of the needle body 2a in this position. If the lancet system is inserted into the puncture aid, the circumference of the puncture aid is selected such that the ring 96 cannot be inserted into the lancet system. When the lancet system is inserted into the lancing aid by means of the lower edge 97 as an abutment flange for the lancing aid housing, the ring is pressed down relative to the needle body into the region of the lancet tip. Thus, the spring-mounted locking arm 90 is released from the ring. The pressing arm is now in a deployed state in the penetration aid and presses against the inner housing wall 98 of the penetration aid. When the lancet system is removed from the lancing aid in use, the locking arm 90 slides along the inclined housing wall 98 in the tapered region of the housing of the lancing aid and is first pressed into the recess 95 of the needle body due to the inclined wall 98. The lancet system can therefore be easily removed from the tapering region of the penetration aid. The used lancet system then assumes the modified form shown in fig. 7 c. When the system is reinserted into the lancing aid, the locking arm 90 is now unfolded and the circumference of the needle body 2a is thereby increased in the region 35, thus preventing the lancet system from being inserted into the front narrow region of the lancing aid.

Claims (21)

1. A penetration assisting device for forming an opening in skin comprising:

a housing into which the lancet system is at least partially insertable,

the housing further comprises a retaining element interacting with a corresponding retaining element of the lancet system, such that the lancet system is positioned in the housing at a defined position, an

The housing includes an opening through which a tip of at least one needle emerges from the lancet system during a puncturing operation, an

A drive mechanism for advancing the at least one needle such that the needle moves from a rest position to a penetration position, an

The needle is connected to the needle body in such a manner that the protective part of the needle body and the needle are movable relative to each other, an

The protective portion of the needle body at least partially surrounds the needle tip in a first position, an

The protective portion of the needle body and the needle tip are arranged in a second position relative to each other in such a way that the needle tip is released from the protective portion of the needle body, and

the needle body further comprises a blocking mechanism which is activated by interaction with the puncture aid and modifies the needle body in such a way that, after the lancet system has been ejected from the puncture aid, the retaining element of the puncture aid is prevented from interacting with the retaining element of the lancet system when the lancet system is reinserted again.

2. A lancing aid according to claim 1,

the retaining element of the puncture aid is prevented from interacting with the retaining element of the lancet system in such a way that the lancet system cannot be reinserted into the puncture aid.

3. A lancing aid according to claim 1,

the lancet system and the piercing aid each have a plurality of independently acting holding elements.

4. A lancing aid according to claim 1, 2 or 3,

the blocking mechanism prevents the holding element of the lancet system from interacting with the piercing aid in such a way that the lancet system cannot be held and positioned at any location in the piercing aid.

5. A lancing aid according to claim 1,

interaction of the holding element of the penetration aid and the lancet system is prevented in such a way that the needle cannot be pushed in by the drive mechanism.

6. A lancing aid according to claim 1,

the blocking mechanism spatially separates the retaining element when the lancet system is reinserted into the puncture assistance device.

7. A lancing aid according to claim 1,

the blocking mechanism is activated when the lancet system is ejected from the piercing aid.

8. A lancing aid according to claim 1,

the blocking mechanism is activated when the lancet system is inserted into the penetration assisting device.

9. A lancing aid according to claim 1,

the blocking mechanism is actuated during the puncturing operation.

10. A lancing aid according to claim 1,

during ejection of the lancet system, the protective portion of the needle moves to its first position.

11. A lancing aid according to claim 1,

said first position of the protective part of the needle is the same as the rest position.

12. A lancet system for insertion into a lancing aid, comprising:

at least one needle with a needle tip for forming a skin opening, and

a needle body with a holding element which interacts with the holding element of the puncture-assisting device when the lancet system is inserted into the puncture-assisting device in such a way that the lancet system is positioned in the housing at a defined position, and

the needle body and the needle are connected in such a way that at least one protective part of the needle body and the needle are movable relative to each other,

wherein the content of the first and second substances,

the protective portion of the needle body at least partially surrounds the needle tip in a first position, an

In a second position, the protective portion of the needle body and the needle tip are spatially separated from each other so that the needle tip is released by the protective portion of the needle body, and

the needle body further comprises a blocking mechanism which is activated by interaction with the puncture aid and modifies the needle body in such a way that, after the lancet system has been ejected from the puncture aid, the retaining element is prevented from interacting with the retaining element of the lancet system when the lancet system is reinserted again.

13. The lancet system of claim 12,

the blocking mechanism changes the shape of the needle body.

14. The lancet system of claim 12,

the protective portion of the needle body is a reservoir housing shell containing a plurality of needles.

15. The lancet system of claim 12,

the needle body includes a plurality of portions.

16. The lancet system of claim 12 or 15,

a portion of the needle body comprises the blocking mechanism, which is actuated independently of the protective portion of the needle body.

17. The lancet system of claim 12, wherein the blocking mechanism acts directly on and covers or breaks the retaining element.

18. The lancet system of claim 12,

the needle body itself is shaped as a holding element.

19. The lancet system of claim 12,

the blocking mechanism has a reset rupture point that ruptures the needle when the needle is ejected from the lancet system.

20. The lancet system of claim 12,

the blocking mechanism increases at least one area of the needle body.

21. The lancet system of claim 12,

the blocking mechanism reduces the size of at least one region of the needle body.